hdoj 1875 畅通工程再续

//9403289    2013-10-24 17:00:49    Accepted    1875    62MS    376K    2205 B    C++    空信高手
#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;
#define typec double
#define V 101
const typec inf=10000000;
int vis[V];
typec lowc[V],cost[V][V];
typedef struct
{
int x;
int y;
} POINT;
POINT pnts[V];
/*=================================================*\
| Prim求MST
| INIT: cost[][]耗费矩阵(inf为无穷大);
| CALL: prim(cost, n); 返回-1代表原图不连通;
\*==================================================*/
typec prim(int n)
{
int i,j,p;
typec minc,res=0;
memset(vis,0,sizeof(vis));
vis[0]=1;
for(i=1; i<n; i++) lowc[i]=cost[0][i];
for(i=1; i<n; i++)
{
minc=inf;
p=-1;
for(j=0; j<n; j++)
{
if(0==vis[j]&&minc>lowc[j])
{
minc=lowc[j];
p=j;
}
}
if(inf==minc) return -1;
res+=minc;
vis[p]=1;
for(j=0; j<n; j++)
if(0==vis[j]&&lowc[j]>cost[p][j])lowc[j]=cost[p][j];
}
return res;
}

double calDis(POINT a,POINT b)
{
return sqrt(double((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)));
}
void Init()
{
int i,j;
for(i=0; i<V; i++)
for(j=0; j<V; j++)
cost[i][j]=10000000;
}
int main()
{
// freopen("input.txt","r",stdin);
int n,i,j;
while(cin>>n&&n!=0)
{
while(n--)
{
int m;
double Sum=0;
cin>>m;
Init();
//memset(cost,inf,sizeof(cost));

for(i=0; i<m; i++)
cin>>pnts[i].x>>pnts[i].y;
for(i=0; i<m; i++)
for(j=0; j<m; j++)
{
if(calDis(pnts[i],pnts[j])<=1000.000001&&calDis(pnts[i],pnts[j])>=10.000000)
cost[i][j]=calDis(pnts[i],pnts[j]);
}
//            if(!flag) cout<<setiosflags(ios::fixed)<<setprecision(1)<<prim(m)*100<<endl;
//            else cout<<"oh!"<<endl;
Sum=prim(m);
if(Sum<0) cout<<"oh!"<<endl;
else cout<<setiosflags(ios::fixed)<<setprecision(1)<<Sum*100<<endl;
}
}
return 0;
}